Heavy metal contents of the cultivated culinary-medicinal Royal Sun Agaricus (the himematsutake mushroom) Agaricus brasiliensis S. Wasser et al. (agaricomycetideae) using different casing materials

The levels of heavy metals (Cd, Hg, As, and Pb) in the fruiting bodies of cultivated Agaricus brasiliensis using various medium (bagasse compost and peat) as casing materials were determined. Time to first primordia formation and first flush for the casing materials after casing was obviously different-21.6 and 26.3 days for peat, followed by 30.3 and 34.3 days for bagasse compost, whereas for ocher, no fruiting body was produced. According to the results, the higher yield was obtained from peat casing. The concentrations of investigated heavy metals in mushroom cased by peat were found to be 4.30 mu g/g for Cd and 0.08 mu g/g for Hg, whereas concentrations of As and Pb were not detected. Those of mushrooms cased by bagasse compost were found to be 6.20 mu g/g for Cd and 0.11 mu g/g for Hg. Again, concentrations of As and Pb were not detected. It was obvious that using peat as a casing material for cultivation of A. brasiliensis was acceptable for assured yield and lower levels of heavy metals in the fruiting bodies.